Spain and Portugal Blackout Sparks Energy Security Concerns Across Europe

On Monday, April 28, a historic blackout swept across Spain and Portugal, leaving most of the Iberian Peninsula without electricity. Beginning around 12:30 PM, communications systems began failing and homes were plunged into darkness in an event without precedent in Spain’s modern history. Power was gradually restored throughout the evening, although much of the population spent the day in darkness. Despite widespread chaos, the night remained calm under a significant police presence.

Although such an event had never before occurred in Spain, it had been flagged as a possibility in official European studies. The 2024 European Resource Adequacy Assessment (ERAA) report, prepared by the European Network of Transmission System Operators for Electricity (ENTSO-E), had warned of blackout risks in Spain and other European countries during peak hours.

The ERAA report detailed the evolving nature of power generation, noting that “significant volumes of fossil fuel-based capacity are likely to become economically unviable by 2030 due to the rise of renewables.” However, it cautioned that “measures are necessary to maintain the security of electricity supply across Europe.” While the report did not specifically forecast risks for 2025, it warned of supply vulnerabilities for 2026, 2028, and 2030, as major energy capacities face decommissioning risks.

ENTSO-E urged authorities to monitor energy system developments closely to ensure investment needs are met and recommended mitigation strategies to safeguard Europe’s energy adequacy.

Nuclear Debate Adds Complexity

The blackout comes amid growing debate over Spain’s nuclear energy future. Under Spain’s National Energy and Climate Plan (PNIEC), the country’s nuclear power plants — including Almaraz I & II, Ascó I & II, Cofrentes, Trillo, and Vandellós II — are scheduled for gradual closure between 2027 and 2035. Although the ERAA report focused primarily on electrical plants rather than nuclear specifically, it stressed that the dismantling of existing generation facilities must be carefully managed to prevent supply gaps.

The report further suggested that adding more than 50 GW of flexible fossil gas capacity could help buffer supply shortages, especially during peak demand events, although it emphasized that such shortages are expected to be rare by 2035.

Future Blackout Risks?

According to the ERAA, the risk of blackouts will peak in 2028, when Spain could face up to 4.8 hours annually of potential supply shortfalls. By 2030, however, the risk should diminish as renewable energy infrastructure becomes more fully developed. Still, ENTSO-E called for improvements to the ERAA methodology to provide policymakers with better tools for strategic planning.

Red Eléctrica’s Previous Dismissal

Interestingly, just 20 days before the blackout, Spain’s national grid operator, Red Eléctrica, firmly denied any risk of such an event. In a post on its official ‘X’ account on April 9, the company asserted: “There is no risk of blackout.” Addressing the ERAA report, Red Eléctrica interpreted it differently, emphasizing that “the main conclusion of the ERAA 2024 is that a significant volume of combined-cycle plants could become economically unviable without appropriate incentives,” rather than predicting immediate supply shortages.

This massive disruption now raises new questions about the resilience of Spain and Portugal’s energy systems — and whether the current pace of the energy transition needs stronger safeguards to ensure reliability.